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C C Ch h ha apter 1 Introducing VMware vSphere 5.5 Now in its fth generation, VMware vSphere 5.5 builds on previous generations of VMware’s enterprise-grade virtualization products. vSphere 5.5 extends fine-grained resource allocation controls to more types of resources, enabling VMware administrators to have even greater con- trol over how resources are allocated to and used by virtual workloads. With dynamic resource controls, high availability, unprecedented fault-tolerance features, distributed resource manage- ment, and backup tools included as part of the suite, IT administrators have all the tools they need to run an enterprise environment ranging from a few servers to thousands of servers. In this chapter, you will learn to Identify the role of each product in the vSphere product suite Recognize the interaction and dependencies between the products in the vSphere suite Understand how vSphere differs from other virtualization products Exploring VMware vSphere 5.5 The VMware vSphere product suite is a comprehensive collection of products and features that together provide a full array of enterprise virtualization functionality. The vSphere product suite includes the following products and features: VMware ESXi VMware vCenter Server vSphere Update Manager VMware vSphere Client and vSphere Web Client VMware vCenter Orchestrator vSphere Virtual Symmetric Multi-Processing vSphere vMotion and Storage vMotion vSphere Distributed Resource Scheduler (DRS) vSphere Storage DRS Storage I/O Control and Network I/O Control Profile-driven storage COPYRIGHTED MATERIAL

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CCChhhaapter 1

g pIntroducing VMware vSphere 5.5Now in its fi fth generation, VMware vSphere 5.5 builds on previous generations of VMware’s

enterprise-grade virtualization products. vSphere 5.5 extends fi ne-grained resource allocation

controls to more types of resources, enabling VMware administrators to have even greater con-

trol over how resources are allocated to and used by virtual workloads. With dynamic resource

controls, high availability, unprecedented fault-tolerance features, distributed resource manage-

ment, and backup tools included as part of the suite, IT administrators have all the tools they

need to run an enterprise environment ranging from a few servers to thousands of servers.

In this chapter, you will learn to

◆ Identify the role of each product in the vSphere product suite

◆ Recognize the interaction and dependencies between the products in the vSphere suite

◆ Understand how vSphere differs from other virtualization products

Exploring VMware vSphere 5.5The VMware vSphere product suite is a comprehensive collection of products and features that

together provide a full array of enterprise virtualization functionality. The vSphere product

suite includes the following products and features:

◆ VMware ESXi

◆ VMware vCenter Server

◆ vSphere Update Manager

◆ VMware vSphere Client and vSphere Web Client

◆ VMware vCenter Orchestrator

◆ vSphere Virtual Symmetric Multi-Processing

◆ vSphere vMotion and Storage vMotion

◆ vSphere Distributed Resource Scheduler (DRS)

◆ vSphere Storage DRS

◆ Storage I/O Control and Network I/O Control

◆ Profi le-driven storage

COPYRIG

HTED M

ATERIAL

2 | CHAPTER 1 INTRODUCING VMWARE VSPHERE 5.5

◆ vSphere High Availability (HA)

◆ vSphere Fault Tolerance (FT)

◆ vSphere Storage APIs for Data Protection and VMware Data Protection

◆ Virtual SAN (VSAN)

◆ vSphere Replication

◆ Flash Read Cache

Rather than waiting to introduce these products and features in their own chapters, we will

introduce each product or feature in the following sections. This will allow us to explain how

each one affects the design, installation, and confi guration of your virtual infrastructure. After

we cover the features and products in the vSphere suite, you’ll have a better grasp of how each

of them fi ts into the design and the big picture of virtualization.

Certain products outside the vSphere product suite extend the vSphere product line with

new functionality. These additional products include VMware Horizon View, VMware vCloud

Director, VMware vCloud Automation Center, and VMware vCenter Site Recovery Manager,

just to name a few. VMware even offers bundles of vSphere and these other products in the

vCloud Suite to make it easier for users to purchase and consume the products in their

environments. However, because of the size and scope of these products, they are not covered

in this book.

As of the writing of this book, VMware vSphere 5.5 is the latest release of the VMware

vSphere product family. This book covers functionality found in version 5.5. Where possible,

we’ve tried to note differences between vSphere 5.0 or 5.1 and vSphere 5.5. For detailed informa-

tion on VMware vSphere 5.0, refer to Mastering VMware vSphere 5, also published by Sybex (2011). 5(If you are still running vSphere 4.x, Sybex also offers Mastering VMware vSphere 4 [2009].)

To help simplify navigation and to help you fi nd information on the breadth of products and

features in the vSphere product suite, we’ve prepared Table 1.1, which contains cross-references

to where you can fi nd more information about a particular product or feature elsewhere in

the book.

Table 1.1: Product and feature cross-references

VMware vSphere Product orFeature More Information Found in This Chapter

VMware ESXi Installation – Chapter 2

Networking – Chapter 5

Storage – Chapter 6

VMware vCenter Server Installation – Chapter 3

Networking – Chapter 5

Storage – Chapter 6

Security – Chapter 8

vSphere Update Manager Chapter 4

EXPLORING VMWARE VSPHERE 5.5 | 3

VMware vSphere Product orFeature More Information Found in This Chapter

vSphere Client and vSphere Web Client Installation – Chapter 2 (vSphere Client)

Installation – Chapter 3 (Web Client)

Usage – Chapter 3

VMware vCenter Orchestrator Chapter 14

vSphere Virtual Symmetric Multi-Processing Chapter 9

vSphere vMotion and Storage vMotion Chapter 12

vSphere Distributed Resource Scheduler Chapter 12

vSphere Storage DRS Chapter 12

Storage I/O Control and Network I/O Control Chapter 11

Profi le-driven storage Chapter 6

vSphere High Availability Chapter 7

vSphere Fault Tolerance Chapter 7

vSphere Storage APIs for Data Protection Chapter 7

VMware Data Protection Chapter 7

VSAN Chapter 6

vSphere Replication Chapter 7

Flash Read Cache Installation – Chapter 6

Usage – Chapter 11

First we’ll look at the actual products that make up the VMware vSphere product suite, and

then we’ll examine the major features. Let’s start with the products in the suite; in particular,

let’s start with VMware ESXi.

Examining the Products in the vSphere SuiteIn the following sections, we’ll describe and review the products found in the vSphere product

suite.

VMware ESXiThe core of the vSphere product suite is the hypervisor, which is the virtualization layer that

serves as the foundation for the rest of the product line. In vSphere 5 and later, including

vSphere 5.5, the hypervisor comes in the form of VMware ESXi.

Table 1.1: Product and feature cross-references (continued)

4 | CHAPTER 1 INTRODUCING VMWARE VSPHERE 5.5

Long-time users of VMware vSphere may recognize this as a shift in the way VMware pro-

vides the hypervisor. Prior to vSphere 5, the hypervisor was available in two forms: VMware

ESX and VMware ESXi. Although both products shared the same core virtualization engine,

supported the same set of virtualization features, leveraged the same licenses, and were con-

sidered bare-metal installation hypervisors (also referred to as Type 1 hypervisors; see the

sidebar titled “Type 1 and Type 2 Hypervisors”), there were still notable architectural differ-

ences. In VMware ESX, VMware used a Linux-derived Service Console to provide an interactive

environment through which users could interact with the hypervisor. The Linux-based Service

Console also included services found in traditional operating systems, such as a fi rewall, Simple

Network Management Protocol (SNMP) agents, and a web server.

Type and Type Hypervisors

Hypervisors are generally grouped into two classes: Type 1 hypervisors and Type 2 hypervi-sors. Type 1 hypervisors run directly on the system hardware and thus are often referred to as bare-metal hypervisors. Type 2 hypervisors require a host operating system, and the host oper-ating system provides I/O device support and memory management. VMware ESXi is a Type 1 bare-metal hypervisor. (In earlier versions of vSphere, VMware ESX was also considered a Type 1 bare-metal hypervisor.) Other Type 1 bare-metal hypervisors include KVM (part of the open-source Linux kernel), Microsoft Hyper-V, and products based on the open-source Xen hypervisor like Citrix XenServer and Oracle VM.

VMware ESXi, on the other hand, is the next generation of the VMware virtualization foun-

dation. Unlike VMware ESX, ESXi installs and runs without the Linux-based Service Console.

This gives ESXi an ultralight footprint of approximately 70 MB. Despite the lack of the Service

Console, ESXi provides all the same virtualization features that VMware ESX supported in ear-

lier versions. Of course, ESXi 5.5 has been enhanced from earlier versions to support even more

functionality, as you’ll see in this chapter and in future chapters.

The key reason that VMware ESXi is able to support the same extensive set of virtualiza-

tion functionality as VMware ESX without the Service Console is that the core of the virtu-

alization functionality wasn’t (and still isn’t) found in the Service Console. It’s the VMkernelthat is the foundation of the virtualization process. It’s the VMkernel that manages the virtual

machines’ (VMs’) access to the underlying physical hardware by providing CPU scheduling,

memory management, and virtual switch data processing. Figure 1.1 shows the structure of

VMware ESXi.

We mentioned earlier that VMware ESXi 5.5 is enhanced over earlier releases. One such area

of enhancement is in the confi guration limits of what the hypervisor is capable of supporting.

Table 1.2 shows the confi guration maximums for the last few versions of VMware ESX/ESXi.

EXPLORING VMWARE VSPHERE 5.5 | 5

Table 1.2: VMware ESXi maximums

Component

VMware ESXi . Maximum

VMware ESXi .Maximum VMware ESX/ESXi . Maximum

Number of virtual CPUs per host

4,096 2,048 512

Number of logicalCPUs (hyper-threading enabled)

320 160 64

Number of virtual CPUs per core

32 25 20 (increased to 25 in Update 1)

Amount of RAM per host

4TB 2 TB 1 TB

Figure 1.1Th e VMkernel is the foundation of the virtualization functionality foundin VMware ESXi VMkernel

These are just some of the confi guration maximums. Where appropriate, future chapters will

include additional values for VMware ESXi maximums for network interface cards (NICs), stor-

age, VMs, and so forth.

Given that VMware ESXi is the foundation of virtualization within the vSphere product suite,

you’ll see content for VMware ESXi throughout the book. Table 1.1, earlier in this chapter, tells

6 | CHAPTER 1 INTRODUCING VMWARE VSPHERE 5.5

you where you can fi nd more information about specifi c features of VMware ESXi elsewhere in

the book.

VMware vCenter ServerStop for a moment to think about your current network. Does it include Active Directory? There

is a good chance it does. Now imagine your network without Active Directory, without the ease

of a centralized management database, without the single sign-on capabilities, and without the

simplicity of groups. That is what managing VMware ESXi hosts would be like without using

VMware vCenter Server. Not a very pleasant thought, is it? Now calm yourself down, take a

deep breath, and know that vCenter Server, like Active Directory, is meant to provide a central-

ized management platform and framework for all ESXi hosts and their respective VMs. vCenter

Server allows IT administrators to deploy, manage, monitor, automate, and secure a virtual

infrastructure in a centralized fashion. To help provide scalability, vCenter Server leverages a

backend database (Microsoft SQL Server and Oracle are both supported, among others) that

stores all the data about the hosts and VMs.

In previous versions of VMware vSphere, vCenter Server was a Windows-only application.

Version 5.5 of vSphere still offers this Windows-based installation of vCenter Server but also

offers a prebuilt vCenter Server Appliance (a virtual appliance, in fact, something you’ll learn

about in Chapter 10, “Using Templates and vApps”) that is based on Linux. Having a Linux-

based vCenter Server Appliance is a great alternative for organizations that don’t wish to deploy

a Windows Server instance just to manage the vSphere environment.

vCenter Server not only provides confi guration and management capabilities—which

include features such as VM templates, VM customization, rapid provisioning and deploy-

ment of VMs, role-based access controls, and fi ne-grained resource allocation controls—it also

provides the tools for the more advanced features of vSphere vMotion, vSphere Distributed

Resource Scheduler, vSphere High Availability, and vSphere Fault Tolerance. All of these fea-

tures are described briefl y in this chapter and in more detail in later chapters.

In addition to vSphere vMotion, vSphere Distributed Resource Scheduler, vSphere High

Availability, and vSphere Fault Tolerance, using vCenter Server to manage ESXi hosts enables a

number of other features:

◆ Enhanced vMotion Compatibility (EVC), which leverages hardware functionality from

Intel and AMD to enable greater CPU compatibility between servers grouped into vSphere

DRS clusters

◆ Host profi les, which allow administrators to bring greater consistency to host confi gura-

tions across larger environments and to identify missing or incorrect confi gurations

◆ Storage I/O Control, which provides cluster-wide quality of service (QoS) controls so that

administrators can ensure that critical applications receive suffi cient I/O resources even

during times of congestion

◆ vSphere Distributed Switches, which provide the foundation for networking settings and

third-party virtual switches that span multiple hosts and multiple clusters

◆ Network I/O Control, which allows administrators to fl exibly partition physical NIC

bandwidth and provide QoS for different types of traffi c

EXPLORING VMWARE VSPHERE 5.5 | 7

◆ vSphere Storage DRS, which enables VMware vSphere to dynamically migrate storage

resources to meet demand, much in the same way that DRS balances CPU and memory

utilization

vCenter Server plays a central role in any sizable VMware vSphere implementation. In

Chapter 3, “Installing and Confi guring vCenter Server,” we discuss planning and installing

vCenter Server as well as look at ways to ensure its availability. Chapter 3 will also examine the

differences between the Windows-based version of vCenter Server and the Linux-based vCenter

Server virtual appliance. Because of vCenter Server’s central role in a VMware vSphere deploy-

ment, we’ll touch on vCenter Server in almost every chapter throughout the rest of the book.

Refer to Table 1.1 previously in this chapter for specifi c cross-references.

vCenter Server is available in three packages:

◆ vCenter Server Essentials is integrated into the vSphere Essentials kits for small offi ce

deployment.

◆ vCenter Server Standard provides all the functionality of vCenter Server, including provi-

sioning, management, monitoring, and automation.

◆ vCenter Server Foundation is like vCenter Server Standard but is limited to managing

three ESXi hosts and does not include vCenter Orchestrator or support for linked-mode

operation.

You can fi nd more information on licensing and product editions for VMware vSphere in the

section “Licensing VMware vSphere.”

vSphere Update ManagervSphere Update Manager is an add-on package for vCenter Server that helps users keep their

ESXi hosts and select VMs patched with the latest updates. vSphere Update Manager provides

the following functionality:

◆ Scans to identify systems that are not compliant with the latest updates

◆ User-defi ned rules for identifying out-of-date systems

◆ Automated installation of patches for ESXi hosts

◆ Full integration with other vSphere features like Distributed Resource Scheduler

vSphere Update Manager works with the Windows-based installation of vCenter Server as

well as the prepackaged vCenter Server virtual appliance. Refer to Table 1.1 for more informa-

tion on where vSphere Update Manager is described in this book.

VMware vSphere Web Client and vSphere ClientvCenter Server provides a centralized management framework for VMware ESXi hosts, but it’s

the vSphere Web Client (and its predecessor, the Windows-based vSphere Client) where vSphere

administrators will spend most of their time.

With the release of vSphere 5, VMware shifted its primary administrative interface to a

robust new vSphere Web Client. The vSphere Web Client provides a dynamic, web-based user

8 | CHAPTER 1 INTRODUCING VMWARE VSPHERE 5.5

interface for managing a virtual infrastructure and enables vSphere administrators to manage

their infrastructure without needing to install the Windows-based vSphere Client on a system.

In its initial release, the vSphere Web Client provided a subset of the functionality available

to the “full” Windows-based vSphere Client. However, in subsequent releases—including the

5.5 release—the vSphere Web Client has been enhanced and expanded to include almost all

the functionality a vSphere administrator needs to manage a vSphere environment. Further,

VMware has stated that the vSphere Web Client will eventually replace the Windows-based

vSphere Client entirely. For this reason, we’ll use screen shots of the vSphere Web Client

throughout this book unless it is impossible to do so.

The Windows-based vSphere Client is still available to allow you to manage ESXi hosts,

either directly or through an instance of vCenter Server, but VMware’s development efforts

are focused on the vSphere Web Client. You can install the vSphere Client by browsing to the

URL of an ESXi host or vCenter Server and selecting the appropriate installation link (although

keep in mind that Internet access might be required in order to download the client in some

instances). The vSphere Client provides a rich graphical user interface (GUI) for all day-to-day

management tasks and for the advanced confi guration of a virtual infrastructure. While you can

connect the vSphere Client either directly to an ESXi host or to an instance of vCenter Server,

the full set of management capabilities are available only when you are connecting the vSphere

Client to vCenter Server.

As we mentioned earlier, the vSphere Web Client is the stated future direction for VMware

vSphere’s management interface. For that reason, we focus primarily on how to use the vSphere

Web Client throughout this book. Tasks in the vSphere Client should be similar, but note that

some tasks can be performed only in the vSphere Web Client, not the Windows-based vSphere

Client.

VMware vCenter OrchestratorVMware vCenter Orchestrator is a workfl ow automation engine that is automatically installed

with every instance of vCenter Server. Using vCenter Orchestrator, vSphere administrators can

build automated workfl ows for a wide variety of tasks available within vCenter Server. The

automated workfl ows you build using vCenter Orchestrator range from simple to complex.

VMware also makes vCenter Orchestrator plug-ins to extend the functionality to include manip-

ulating Microsoft Active Directory, Cisco’s Unifi ed Computing System (UCS), and VMware

vCloud Director. This makes vCenter Orchestrator a powerful tool to use in building automated

workfl ows in the virtualized data center.

Now that we’ve discussed the specifi c products in the VMware vSphere product suite, we’d

like to take a closer look at some of the signifi cant features.

Examining the Features in VMware vSphereIn the following sections, we’ll take a closer look at some of the features that are available in the

vSphere product suite. We’ll start with Virtual SMP.

vSphere Virtual Symmetric Multi-ProcessingThe vSphere Virtual Symmetric Multi-Processing (vSMP or Virtual SMP) product allows vir-

tual infrastructure administrators to construct VMs with multiple virtual processors. vSphere

Virtual SMP is not the licensing product that allows ESXi to be installed on servers with multiple

processors; it is the technology that allows the use of multiple processors inside a VM. Figure

EXPLORING VMWARE VSPHERE 5.5 | 9

1.2 identifi es the differences between multiple processors in the ESXi host system and multiple

virtual processors.

Figure 1.2vSphere Virtual SMP allows VMsto be created withmore than one virtual CPU.

VMkernel

Virtual SMP

With vSphere Virtual SMP, applications that require and can actually use multiple CPUs can

be run in VMs confi gured with multiple virtual CPUs. This allows organizations to virtual-

ize even more applications without negatively impacting performance or being unable to meet

service-level agreements (SLAs).

In vSphere 5, VMware expanded this functionality by also allowing users to specify multiple

virtual cores per virtual CPU. Using this feature, a user could provision a dual “socket” VM

with two cores per “socket” for a total of four virtual cores. This gives users tremendous fl exibil-

ity in carving up CPU processing power among the VMs.

vSphere vMotion and vSphere Storage vMotionIf you have read anything about VMware, you have most likely read about the extremely useful

feature called vMotion. vSphere vMotion, also known as live migration, is a feature of ESXi and

vCenter Server that allows an administrator to move a running VM from one physical host to

another physical host without having to power off the VM. This migration between two physical

hosts occurs with no downtime and with no loss of network connectivity to the VM. The ability

to manually move a running VM between physical hosts on an as-needed basis is a powerful

feature that has a number of use cases in today’s datacenters.

Suppose a physical machine has experienced a nonfatal hardware failure and needs to be

repaired. Administrators can easily initiate a series of vMotion operations to remove all VMs

from an ESXi host that is to undergo scheduled maintenance. After the maintenance is complete

and the server is brought back online, administrators can utilize vMotion to return the VMs to

the original server.

Alternately, consider a situation in which you are migrating from one set of physical serv-

ers to a new set of physical servers. Assuming that the details have been addressed—and we’ll

discuss the details around vMotion in Chapter 12, “Balancing Resource Utilization”—you can

10 | CHAPTER 1 INTRODUCING VMWARE VSPHERE 5.5

use vMotion to move the VMs from the old servers to the newer servers, making quick work of a

server migration with no interruption of service.

Even in normal day-to-day operations, vMotion can be used when multiple VMs on the same

host are in contention for the same resource (which ultimately is causing poor performance

across all the VMs). vMotion can solve the problem by allowing an administrator to migrate any

VMs that are facing contention to another ESXi host with greater availability for the resource in

demand. For example, when two VMs are in contention with each other for CPU resources, an

administrator can eliminate the contention by using vMotion to move one of the VMs to an ESXi

host that has more available CPU resources.

vMotion moves the execution of a VM, relocating the CPU and memory footprint between

physical servers but leaving the storage untouched. Storage vMotion builds on the idea and

principle of vMotion by providing the ability to leave the CPU and memory footprint untouched

on a physical server but migrating a VM’s storage while the VM is still running.

Deploying vSphere in your environment generally means that lots of shared storage—Fibre

Channel or iSCSI SAN or NFS—is needed. What happens when you need to migrate from an

older storage array to a newer storage array? What kind of downtime would be required? Or

what about a situation where you need to rebalance utilization of the array, either from a capac-

ity or performance perspective?

vSphere Storage vMotion directly addresses these situations. By providing the ability to

move the storage for a running VM between datastores, Storage vMotion enables administra-

tors to address all of these situations without downtime. This feature ensures that outgrowing

datastores or moving to a new SAN does not force an outage for the affected VMs and provides

administrators with yet another tool to increase their fl exibility in responding to changing busi-

ness needs.

vSphere Distributed Resource SchedulervMotion is a manual operation, meaning that an administrator must initiate the vMotion opera-

tion. What if VMware vSphere could perform vMotion operations automatically? That is the

basic idea behind vSphere Distributed Resource Scheduler (DRS). If you think that vMotion

sounds exciting, your anticipation will only grow after learning about DRS. DRS, simply put,

leverages vMotion to provide automatic distribution of resource utilization across multiple ESXi

hosts that are confi gured in a cluster.

Given the prevalence of Microsoft Windows Server in today’s datacenters, the use of the

term cluster often draws IT professionals into thoughts of Microsoft Windows Server clusters.

Windows Server clusters are often active-passive or active-active-passive clusters. However,

ESXi clusters are fundamentally different, operating in an active-active mode to aggregate and

combine resources into a shared pool. Although the underlying concept of aggregating physical

EXPLORING VMWARE VSPHERE 5.5 | 11

hardware to serve a common goal is the same, the technology, confi guration, and feature sets

are quite different between VMware ESXi clusters and Windows Server clusters.

Aggregate Capacity and Single Host Capacity

Although we say that a DRS cluster is an implicit aggregation of CPU and memory capacity, it’s important to keep in mind that a VM is limited to using the CPU and RAM of a single physical host at any given time. If you have two ESXi servers with 32 GB of RAM each in a DRS cluster, the cluster will correctly report 64 GB of aggregate RAM available, but any given VM will not be able to use more than approximately 32 GB of RAM at a time.

An ESXi cluster is an implicit aggregation of the CPU power and memory of all hosts

involved in the cluster. After two or more hosts have been assigned to a cluster, they work in

unison to provide CPU and memory to the VMs assigned to the cluster (keeping in mind that

any given VM can only use resources from one host; see the sidebar titled “Aggregate Capacity

and Single Host Capacity”). The goal of DRS is twofold:

◆ At startup, DRS attempts to place each VM on the host that is best suited to run that VM at

that time.

◆ While a VM is running, DRS seeks to provide that VM with the required hardware

resources while minimizing the amount of contention for those resources in an effort to

maintain balanced utilization levels.

The fi rst part of DRS is often referred to as intelligent placement. DRS can automate the place-

ment of each VM as it is powered on within a cluster, placing it on the host in the cluster that it

deems to be best suited to run that VM at that moment.

DRS isn’t limited to operating only at VM startup, though. DRS also manages the VM’s loca-

tion while it is running. For example, let’s say three servers have been confi gured in an ESXi

cluster with DRS enabled. When one of those servers begins to experience a high contention for

CPU utilization, DRS detects that the cluster is imbalanced in its resource usage and uses an

internal algorithm to determine which VM(s) should be moved in order to create the least imbal-

anced cluster. For every VM, DRS will simulate a migration to each host and the results will

be compared. The migrations that create the least imbalanced cluster will be recommended or

automatically performed, depending upon DRS’s confi guration.

DRS performs these on-the-fl y migrations without any downtime or loss of network connec-

tivity to the VMs by leveraging vMotion, the live migration functionality we described earlier.

This makes DRS extremely powerful because it allows clusters of ESXi hosts to dynamically

rebalance their resource utilization based on the changing demands of the VMs running on that

cluster.

12 | CHAPTER 1 INTRODUCING VMWARE VSPHERE 5.5

Fewer Bigger Servers or More Smaller Servers?

Remember from Table 1.2 that VMware ESXi supports servers with up to 320 logical CPU cores and up to 4TB of RAM. With vSphere DRS, though, you can combine multiple smaller servers for the purpose of managing aggregate capacity. Th is means that bigger, more-powerful servers might not be better servers for virtualization projects. Th ese larger servers, in general, are signifi cantly more expensive than smaller servers, and using a greater number of smaller servers (often referred to as “scaling out”) may provide greater fl exibility than a smaller number of larger servers (often referred to as “scaling up”). Th e key thing to remember is that a bigger server isn’t necessarily a better server.

vSphere Storage DRSvSphere Storage DRS takes the idea of vSphere DRS and applies it to storage. Just as vSphere

DRS helps to balance CPU and memory utilization across a cluster of ESXi hosts, Storage DRS

helps balance storage capacity and storage performance across a cluster of datastores using

mechanisms that echo those used by vSphere DRS.

We described vSphere DRS’s feature called intelligent placement, which automates the place-

ment of new VMs based on resource usage within an ESXi cluster. In the same fashion, Storage

DRS has an intelligent placement function that automates the placement of VM virtual disks

based on storage utilization. Storage DRS does this through the use of datastore clusters. When

you create a new VM, you simply point it to a datastore cluster, and Storage DRS automatically

places the VM’s virtual disks on an appropriate datastore within that datastore cluster.

Likewise, just as vSphere DRS uses vMotion to balance resource utilization dynamically,

Storage DRS uses Storage vMotion to rebalance storage utilization based on capacity and/or

latency thresholds. Because Storage vMotion operations are typically much more resource inten-

sive than vMotion operations, vSphere provides extensive controls over the thresholds, timing,

and other guidelines that will trigger a Storage DRS automatic migration via Storage vMotion.

Storage I/O Control and Network I/O ControlVMware vSphere has always had extensive controls for modifying or controlling the allocation of

CPU and memory resources to VMs. What vSphere didn’t have prior to the release of vSphere 4.1

was a way to apply these same sort of extensive controls to storage I/O and network I/O. Storage

I/O Control and Network I/O Control address that shortcoming.

Storage I/O Control (SIOC) allows vSphere administrators to assign relative priority to stor-

age I/O as well as assign storage I/O limits to VMs. These settings are enforced cluster-wide;

when an ESXi host detects storage congestion through an increase of latency beyond a user-

confi gured threshold, it will apply the settings confi gured for that VM. The result is that

VMware administrators can ensure that the VMs that need priority access to storage resources

get the resources they need. In vSphere 4.1, Storage I/O Control applied only to VMFS storage;

vSphere 5 extended that functionality to NFS datastores.

EXPLORING VMWARE VSPHERE 5.5 | 13

The same goes for Network I/O Control (NIOC), which provides VMware administrators

with more granular controls over how VMs use network bandwidth provided by the physical

NICs. As the widespread adoption of 10 Gigabit Ethernet continues, Network I/O Control pro-

vides VMware administrators with a way to more reliably ensure that network bandwidth is

properly allocated to VMs based on priority and limits.

Profile-Driven StorageWith profi le-driven storage, vSphere administrators are able to use storage capabilities and VM

storage profi les to ensure that VMs are residing on storage that is able to provide the necessary

levels of capacity, performance, availability, and redundancy. Profi le-driven storage is built on

two key components:

◆ Storage capabilities, leveraging vSphere’s storage awareness APIs

◆ VM storage profi les

Storage capabilities are either provided by the storage array itself (if the array is capable of

using vSphere’s storage awareness APIs) and/or defi ned by a vSphere administrator. These stor-

age capabilities represent various attributes of the storage solution.

VM storage profi les defi ne the storage requirements for a VM and its virtual disks. You create

VM storage profi les by selecting the storage capabilities that must be present for the VM to run.

Datastores that have all the capabilities defi ned in the VM storage profi le are compliant with the

VM storage profi le and represent possible locations where the VM could be stored.

This functionality gives vSphere administrators much greater visibility into storage capabili-

ties and helps ensure that the appropriate functionality for each VM is indeed being provided

by the underlying storage.

Refer to Table 1.1 to fi nd out which chapter discusses profi le-driven storage in more detail.

vSphere High AvailabilityIn many cases, high availability—or the lack of high availability—is the key argument used

against virtualization. The most common form of this argument more or less sounds like this:

“Before virtualization, the failure of a physical server affected only one application or workload.

After virtualization, the failure of a physical server will affect many more applications or work-

loads running on that server at the same time. We can’t put all our eggs in one basket!”

VMware addresses this concern with another feature present in ESXi clusters called vSphere

High Availability (HA). Once again, by nature of the naming conventions (clusters, high avail-

ability), many traditional Windows administrators will have preconceived notions about this

feature. Those notions, however, are incorrect in that vSphere HA does not function like a high-

availability confi guration in Windows. The vSphere HA feature provides an automated process

for restarting VMs that were running on an ESXi host at a time of server failure (or other quali-

fying infrastructure failure, as we’ll describe in Chapter 7, “Ensuring High Availability and

Business Continuity”). Figure 1.3 depicts the VM migration that occurs when an ESXi host that

is part of an HA-enabled cluster experiences failure.

14 | CHAPTER 1 INTRODUCING VMWARE VSPHERE 5.5

Figure 1.3Th e vSphere HA feature will restart any VMs that were previously runningon an ESXi hostthat experiencesserver failure.

ESXi host ESXi host

VM restart

The vSphere HA feature, unlike DRS, does not use the vMotion technology as a means of

migrating servers to another host. vMotion applies only to planned migrations, where both

the source and destination ESXi host are running and functioning properly. In a vSphere

HA failover situation, there is no anticipation of failure; it is not a planned outage, and there-

fore there is no time to perform a vMotion operation. vSphere HA is intended to minimize

unplanned downtime because of the failure of a physical ESXi host or other infrastructure

components. We’ll go into more detail in Chapter 7 on what kinds of failures vSphere HA helps

protect against.

vSphere HA Improvements in vSphere

vSphere HA received a couple of notable improvements in the vSphere 5.0 release. First, scalability was signifi cantly improved; you could run up to 512 VMs per host (up from 100 in earlier versions) and 3,000 VMs per cluster (up from 1,280 in earlier versions). Second, vSphere HA integrated more closely with the intelligent placement functionality of vSphere DRS, giving vSphere HA greater ability to restart VMs in the event of a host failure. Th e third and perhaps most signifi cant improve-ment is the complete rewrite of the underlying architecture for vSphere HA; this entirely new architecture, known as Fault Domain Manager (FDM), eliminated many of the constraints found in earlier versions of VMware vSphere.

By default, vSphere HA does not provide failover in the event of a guest OS failure, although

you can confi gure vSphere HA to monitor VMs and restart them automatically if they fail to

respond to an internal heartbeat. This feature is called VM Failure Monitoring, and it uses a

combination of internal heartbeats and I/O activity to attempt to detect if the guest OS inside a

VM has stopped functioning. If the guest OS has stopped functioning, the VM can be restarted

automatically.

EXPLORING VMWARE VSPHERE 5.5 | 15

With vSphere HA, it’s important to understand that there will be an interruption of service.

If a physical host fails, vSphere HA restarts the VM, and while the VM is restarting, the applica-

tions or services provided by that VM are unavailable. For users who need even higher levels

of availability than can be provided using vSphere HA, vSphere Fault Tolerance (FT), which is

described in the next section, can help.

vSphere Fault ToleranceWhile vSphere HA provides a certain level of availability for VMs in the event of physical host

failure, this might not be good enough for some workloads. vSphere Fault Tolerance (FT) might

help in these situations.

As we described in the previous section, vSphere HA protects against unplanned physi-

cal server failure by providing a way to automatically restart VMs upon physical host failure.

This need to restart a VM in the event of a physical host failure means that some downtime—

generally less than 3 minutes—is incurred. vSphere FT goes even further and eliminates any

downtime in the event of a physical host failure. Using vLockstep technology that is based on

VMware’s earlier “record and replay” functionality, vSphere FT maintains a mirrored secondary

VM on a separate physical host that is kept in lockstep with the primary VM. Everything that

occurs on the primary (protected) VM also occurs simultaneously on the secondary (mirrored)

VM, so that if the physical host for the primary VM fails, the secondary VM can immediately

step in and take over without any loss of connectivity. vSphere FT will also automatically

re-create the secondary (mirrored) VM on another host if the physical host for the secondary

VM fails, as illustrated in Figure 1.4. This ensures protection for the primary VM at all times.

Figure 1.4vSphere FT provides protection against host failures with nodowntime experi-enced by the VMs.

ESXi host ESXi hostLogging connection

VM failover,

no downtime

In the event of multiple host failures—say, the hosts running both the primary and second-

ary VMs failed—vSphere HA will reboot the primary VM on another available server, and

vSphere FT will automatically create a new secondary VM. Again, this ensures protection for

the primary VM at all times.

16 | CHAPTER 1 INTRODUCING VMWARE VSPHERE 5.5

vSphere FT can work in conjunction with vMotion. As of vSphere 5.0, vSphere FT is

also integrated with vSphere DRS, although this feature does require Enhanced vMotion

Compatibility (EVC).

vSphere Storage APIs for Data Protection and VMware Data ProtectionOne of the most critical aspects to any network, not just a virtualized infrastructure, is a solid

backup strategy as defi ned by a company’s disaster recovery and business continuity plan. To

help address organizational backup needs, VMware vSphere 5.0 has two key components: the

vSphere Storage APIs for Data Protection (VADP) and VMware Data Protection (VDP).

VADP is a set of application programming interfaces (APIs) that backup vendors leverage in

order to provide enhanced backup functionality of virtualized environments. VADP enables

functionality like fi le-level backup and restore; support for incremental, differential, and full-

image backups; native integration with backup software; and support for multiple storage

protocols.

On its own, though, VADP is just a set of interfaces, like a framework for making backups

possible. You can’t actually back up VMs with VADP. You’ll need a VADP-enabled backup appli-

cation. There are a growing number of third-party backup applications that are designed to

work with VADP, and VMware also offers its own backup tool, VMware Data Protection (VDP).

VDP leverages VADP and technology based on EMC Avamar to provide a full backup solution

for smaller VMware vSphere environments.

Whither VMware Data Recovery?

In vSphere 5.1, VMware phased out its earlier data protection tool, VMware Data Recovery (VDR), in favor of VMware Data Protection. While VDR was provided with vSphere 5.0, VDR is not sup-ported with vSphere 5.1 and later, and VDP should be used instead.

Virtual SAN (VSAN)VSAN is a major new feature included with vSphere 5.5 and the evolution of work that VMware

has been doing for a few years now. Building on top of the work VMware did with the vSphere

Storage Appliance (VSA), VSAN lets organizations leverage the storage found in all their indi-

vidual compute nodes and turn it into—well, a virtual SAN.NNVSAN requires at least three nodes but will scale to as many as 8 nodes. VSAN also requires

solid-state storage in each of the compute nodes; this is done to help improve I/O performance

given that most compute nodes have a limited number of physical drive spindles present. (Note

that the solid-state storage in the servers used by VSAN is separate from solid-state storage that

EXPLORING VMWARE VSPHERE 5.5 | 17

would be used by vSphere’s Flash Read Cache caching functionality. See the section on Flash

Read Cache later in this chapter for more details on using solid-state storage for caching.) VSAN

pools the storage across the compute nodes, allowing you to create a datastore that spans mul-

tiple compute nodes. VSAN employs algorithms to help protect against data loss, such as ensur-

ing that the data exists on multiple participating VSAN nodes at the same time.

More information on VSAN is found in Chapter 6, “Creating and Confi guring Storage

Devices.”

vSphere ReplicationvSphere Replication brings data replication, a feature typically found in hardware storage plat-

forms, into vSphere itself. It’s been around since vSphere 5.0, when it was only enabled for use in

conjunction with VMware Site Recovery Manager (SRM) 5.0. In vSphere 5.1, vSphere Replication

was decoupled from SRM and enabled for use even without VMware SRM.

vSphere Replication enables customers to replicate VMs from one vSphere environment to

another vSphere environment. Typically, this means from one data center (often referred to as

the primary or production data center) to another data center (typically the secondary, backup,

or disaster recovery [DR] site). Unlike hardware-based solutions, vSphere Replication operates

on a per-VM basis, so it gives customers very granular control over which workloads will be

replicated and which workloads won’t be replicated.

You can fi nd more information about vSphere Replication in Chapter 7.

Flash Read CacheSince the release of vSphere 5.0 in 2011, the industry has seen tremendous uptake in the use

of solid-state storage (also referred to as fl ash storage) across a wide variety of use cases.

Because solid-state storage can provide massive numbers of I/O operations per second

(IOPS) it can handle the increasing I/O demands of virtual workloads. However, solid-state

storage is typically more expensive on a per-gigabyte basis than traditional, hard-disk-based

storage and therefore is often deployed as a caching mechanism to help speed up frequently

accessed data.

Unfortunately, without support in vSphere for managing solid-state storage as a caching

mechanism, vSphere architects and administrators have had diffi culty fully leveraging solid-

state storage in their environments. With the release of vSphere 5.5, VMware addresses that

limitation through a feature called vSphere Flash Read Cache.Flash Read Cache brings full support for using solid-state storage as a caching mechanism

into vSphere. Using Flash Read Cache, administrators can assign solid-state caching space to

VMs much in same manner as VMs are assigned CPU cores, RAM, or network connectivity.

vSphere manages how the solid-state caching capacity is allocated and assigned and how it is

used by the VMs.

Hardware vendors that provide solid-state storage devices have partnered with VMware to

make their products fully support Flash Read Cache.

18 | CHAPTER 1 INTRODUCING VMWARE VSPHERE 5.5

Real World Scenario: VMware vSphere Compared to Hyper-V andXenServer

It’s not really possible to compare some virtualization solutions to other virtualization solutions because they are fundamentally diff erent in approach and purpose. Such is the case with VMware ESXi and some of the other virtualization solutions on the market.

To make accurate comparisons between vSphere and other virtualization solutions, you must include only Type 1 (“bare-metal”) virtualization solutions. Th is would include ESXi, of course, and Microsoft Hyper-V and Citrix XenServer. It would not include products such as VMware Server and Microsoft Virtual Server, both of which are Type 2 (“hosted”) virtualization products. Even within the Type 1 hypervisors, there are architectural diff erences that make direct comparisons diffi cult.

For example, both Microsoft Hyper-V and Citrix XenServer route all the VM I/O through the “parent partition” or “dom0.” Th is typically provides greater hardware compatibility with a wider range of products. In the case of Hyper-V, for example, as soon as Windows Server 2012—the general-purpose operating system running in the parent partition—supports a particular type of hardware, Hyper-V supports it also. Hyper-V “piggybacks” on Windows’s hardware drivers and the I/O stack. Th e same can be said for XenServer, although its “dom0” runs Linux and not Windows.

VMware ESXi, on the other hand, handles I/O within the hypervisor itself. Th is typically provides greater throughput and lower overhead at the expense of slightly more limited hardware compat-ibility. In order to add more hardware support or updated drivers, the hypervisor must be updated because the I/O stack and device drivers are in the hypervisor.

Th is architectural diff erence is fundamental. Nowhere is this architectural diff erence more greatly demonstrated than in ESXi, which has a small footprint yet provides a full-featured virtualization solution. Both Citrix XenServer and Microsoft Hyper-V require a full installation of a general-purpose operating system (Windows Server 2012 for Hyper-V, Linux for XenServer) in the parent partition/dom0 in order to operate.

In the end, each of the virtualization products has its own set of advantages and disadvantages, and large organizations may end up using multiple products. For example, VMware vSphere might be best suited in the large corporate datacenter, while Microsoft Hyper-V or Citrix XenServer might be acceptable for test, development, or branch-offi ce deployment. Organizations that don’t require VMware vSphere’s advanced features like vSphere DRS, vSphere FT, or Storage vMotion may also fi nd that Microsoft Hyper-V or Citrix XenServer is a better fi t for their needs.

As you can see, VMware vSphere offers some pretty powerful features that will change the

way you view the resources in your datacenter. vSphere also has a wide range of features and

functionality. Some of these features, though, might not be applicable to all organizations, which

is why VMware has crafted a fl exible licensing scheme for organizations of all sizes.

Licensing VMware vSphereWith the introduction of VMware vSphere 4, VMware introduced new licensing tiers and bun-

dles that were intended to provide a good fi t for every market segment. That arrangement con-

tinued with vSphere 5.0. However, with vSphere 5.1 (and continuing with vSphere 5.5), VMware

refi ned this licensing arrangement with the introduction of the vCloud Suite—a bundling

EXPLORING VMWARE VSPHERE 5.5 | 19

of products including vSphere, vCloud Automation Center, vCenter Site Recovery Manager,

vCloud Networking and Security, vCloud Director, and vCenter Operations Management Suite.

While licensing vSphere via the vCloud Suite is likely the preferred way of licensing vSphere

moving forward, we don’t have the room in this book to discuss all the other products that are

included in the vCloud Suite. Instead, we’ll focus strictly on vSphere, and we’ll explain how the

various features that we’ve discussed so far fi t into vSphere’s licensing model when vSphere is

licensed standalone.

vSphere or vSOM?

VMware sells “standalone” vSphere in one of two ways; as vSphere, with all the various kits and editions, and as vSphere with Operations Management, referred to as vSOM. vSOM is the same as vSphere but adds the vCenter Operations Management Suite. In this section, we are focused on standalone vSphere only, but keep in mind that vSOM would be licensed and packaged in much the same way.

You’ve already seen how VMware packages and licenses VMware vCenter Server, but here’s

a quick review:

◆ VMware vCenter Server for Essentials, which is bundled with the vSphere Essentials kits

(more on the kits in just a moment).

◆ VMware vCenter Server Foundation supports the management of up to three vSphere

hosts.

◆ VMware vCenter Server Standard, which includes all functionality and does not have a

preset limit on the number of vSphere hosts it can manage (although normal sizing limits

do apply). vCenter Orchestrator is included only in the Standard edition of vCenter Server.

In addition to the three editions of vCenter Server, VMware offers three editions of VMware

vSphere:

◆ vSphere Standard Edition

◆ vSphere Enterprise Edition

◆ vSphere Enterprise Plus Edition

No More vRAM and no vCPU Limits

If you’ve been around the VMware vSphere world for a while, you might recall that VMware introduced the idea of vRAM—the amount of RAM confi gured for a VM—as a licensing constraint with the release of vSphere 5.0. As of vSphere 5.1, and continuing into vSphere 5.5, VMware no longer uses vRAM entitlements as a licensing mechanism. VMware has removed any licensing limits on the number of vCPUs that can be assigned to a VM.

These three editions are differentiated primarily by the features each edition supports,

although there are some capacity limitations with the different editions. Notably missing from

the licensing for vSphere 5.5 are limits on vRAM (see the sidebar titled “No More vRAM”).

20 | CHAPTER 1 INTRODUCING VMWARE VSPHERE 5.5

We’ll summarize the features that are supported for each edition of VMware vSphere 5.5 in

Table 1.3.

Table 1.3: Overview of VMware vSphere product editions

EssentialsEssentials Plus Standard Enterprise

EnterprisePlus

vCenter Servercompatibility

vCenter ServerEssentials

vCenter ServerEssentials

vCenter ServerStandard

vCenter ServerStandard

vCenter ServerStandard

vRAM Entitlement

Unlimited Unlimited Unlimited Unlimited Unlimited

vCPUs per VM 64 64 64 64 64

vMotion X X X X

High Availability

X X X X

VMware Data Protection

X X X X

vSphere Replication

X X X X

vShield Endpoint

X X X X

vSphere Storage Appliance

X X X X

Fault Tolerance (1 vCPU)

X X X

StoragevMotion

X X X

DistributedResourceScheduler and DistributedPowerManagement

X X

Storage APIs forArray Integration,Multipathing

X X

EXPLORING VMWARE VSPHERE 5.5 | 21

EssentialsEssentialsPlus Standard Enterprise

EnterprisePlus

Big DataExtensions

X X

Reliable Memory

X X

DistributedSwitch

X

I/O Controls (Network andStorage) andSR-IOV

X

Host Profi les X

Auto Deploy X

Policy-drivenstorage

X

Storage DRS X

Flash Read Cache

X

App HA X

Source: “VMware vSphere 5.0 Licensing, Pricing and Packaging” white paper published by VMware, available at www.vmware.com.

It’s important to note that all editions of VMware vSphere 5.5 include support for thin pro-

visioning, vSphere Update Manager, and the vSphere Storage APIs for Data Protection. We did

not include them in Table 1.3 because these features are supported in all editions. Because prices

change and vary depending on partner, region, and other factors, we have not included any

pricing information here.

We did not include VSAN in Table 1.3 because it is licensed separately from vSphere.

On all editions of vSphere, VMware requires at least one year of Support and Subscription

(SnS). The only exception is the Essential Kits, as we’ll explain in a moment.

In addition to the different editions described previously, VMware offers some bundles,

referred to as kits. VMware offers Essentials Kits as well as Acceleration Kits.

Essentials Kits are all-in-one solutions for small environments, supporting up to three vSphere

hosts with two CPUs each. To support three hosts with two CPUs each, the Essentials Kits come

with six licenses. All these limits are product-enforced. There are three Essentials Kits available:

◆ VMware vSphere Essentials

Table 1.3: Overview of VMware vSphere product editions (continued)

22 | CHAPTER 1 INTRODUCING VMWARE VSPHERE 5.5

◆ VMware vSphere Essentials Plus

◆ VMware vSphere Essentials for Retail and Branch Offi ces

You can’t buy these kits on a per-CPU basis; they are bundled solutions for three servers.

vSphere Essentials includes one year of subscription; support is optional and available on a per-

incident basis. Like other editions, vSphere Essentials Plus requires at least one year of SnS; this

must be purchased separately and is not included in the bundle.

The Retail and Branch Offi ces (RBO) Kits are differentiated from the “normal” Essentials and

Essentials Plus Kits only by the licensing guidelines. These kits are licensed per site (10 sites

minimum, with a maximum of three hosts per site), and customers can add additional sites as

required. Central management of all the sites via vCenter Server Standard is possible, though

vCenter Server Standard must be purchased separately. vCenter Server Essentials is included.

VMware also has Acceleration Kits, which combine the different components of the vSphere

product suite. There are three Acceleration Kits:

◆ Standard Acceleration Kit: This kit includes one license of vCenter Server Standard plus

licenses for vSphere Standard Edition.

◆ Enterprise Acceleration Kit: The Enterprise Acceleration Kit includes one license of vCen-

ter Server Standard and licenses for vSphere Enterprise Edition.

◆ Enterprise Plus Acceleration Kit: This kit includes both licenses for vSphere Enterprise

Plus Edition and a single license for vCenter Server Standard.

While the Essentials Kits are bundled and treated as a single unit, the Acceleration Kits

merely offer customers an easier way to purchase the necessary licenses in one step.

Now that you have an idea of how VMware licenses vSphere, we’ll review why an organiza-

tion might choose to use vSphere and what benefi ts that organization could see as a result.

Why Choose vSphere?Much has been said and written about the total cost of ownership (TCO) and return on invest-

ment (ROI) for virtualization projects involving VMware virtualization solutions. Rather than

rehashing that material here, we’ll instead focus, briefl y, on why an organization should choose

VMware vSphere as their virtualization platform.

Online TCO Calculator

VMware off ers a web-based TCO calculator that helps you calculate the TCO and ROI for a vir-tualization project using VMware virtualization solutions. Th is calculator is available online at www.vmware.com/go/calculator.

You’ve already read about the various features that VMware vSphere offers. To help you

understand how these features can benefi t your organization, we’ll apply them to the fi ctional

XYZ Corporation. We’ll walk through several different scenarios and look at how vSphere helps

in these scenarios:

Scenario 1 XYZ Corporation’s IT team has been asked by senior management to rap-

idly provision six new servers to support a new business initiative. In the past, this meant

WHY CHOOSE VSPHERE? | 23

ordering hardware, waiting on the hardware to arrive, racking and cabling the equipment

once it arrived, installing the operating system and patching it with the latest updates, and

then installing the application. The time frame for all these steps ranged anywhere from a

few days to a few months and was typically a couple of weeks. Now, with VMware vSphere

in place, the IT team can use vCenter Server’s templates functionality to build a VM, install

the operating system, and apply the latest updates, and then rapidly clone—or copy—this

VM to create additional VMs. Now their provisioning time is down to hours, likely even min-

utes. Chapter 10 discusses this functionality in detail.

Scenario 2 Empowered by the IT team’s ability to quickly respond to the needs of this new

business initiative, XYZ Corporation is moving ahead with deploying updated versions of a

line-of-business application. However, the business leaders are a bit concerned about upgrad-

ing the current version. Using the snapshot functionality present in ESXi and vCenter Server,

the IT team can take a “point-in-time picture” of the VM so that if something goes wrong

during the upgrade, it’s a simple rollback to the snapshot for recovery. Chapter 9, “Creating

and Managing Virtual Machines,” discusses snapshots.

Scenario 3 XYZ Corporation is impressed with the IT team and vSphere’s functionality

and is now interested in expanding its use of virtualization. In order to do so, however, a

hardware upgrade is needed on the servers currently running ESXi. The business is worried

about the downtime that will be necessary to perform the hardware upgrades. The IT team

uses vMotion to move VMs off one host at a time, upgrading each host in turn without incur-

ring any downtime to the company’s end users. Chapter 12 discusses vMotion in more depth.

Scenario 4 After the great success it has had virtualizing its infrastructure with vSphere,

XYZ Corporation now fi nds itself in need of a new, larger shared storage array. vSphere’s sup-

port for Fibre Channel, iSCSI, and NFS gives XYZ room to choose the most cost-effective stor-

age solution available, and the IT team uses Storage vMotion to migrate the VMs without any

downtime. Chapter 12 discusses Storage vMotion.

These scenarios begin to provide some idea of the benefi ts that organizations see when virtu-

alizing with an enterprise-class virtualization solution like VMware vSphere.

What Do I Virtualize with VMware vSphere?

Virtualization, by its very nature, means that you are going to take multiple operating systems—such as Microsoft Windows, Linux, Solaris, or Novell NetWare—and run them on a single physical server. While VMware vSphere off ers broad support for virtualizing a wide range of operating systems, it would be almost impossible for us to discuss how virtualization impacts all the diff er-ent versions of all the diff erent operating systems that vSphere supports.

Because the majority of organizations that adopt vSphere are primarily virtualizing Microsoft Windows, that operating system will receive the majority of attention when it comes to describ-ing procedures that must occur within a virtualized operating system. You will see coverage of tasks for a virtualized installation of Linux as well, but the majority of the coverage will be for Microsoft Windows.

If you are primarily virtualizing something other than Microsoft Windows, VMware provides more in-depth information on all the operating systems it supports and how vSphere interacts with those operating systems on its website at www.vmware.com.

24 | CHAPTER 1 INTRODUCING VMWARE VSPHERE 5.5

Th e Bottom LineIdentify the role of each product in the vSphere product suite. The VMware vSphere

product suite contains VMware ESXi and vCenter Server. ESXi provides the base virtualiza-

tion functionality and enables features like Virtual SMP. vCenter Server provides manage-

ment for ESXi and enables functionality like vMotion, Storage vMotion, vSphere Distributed

Resource Scheduler (DRS), vSphere High Availability (HA), and vSphere Fault Tolerance (FT).

Storage I/O Control and Network I/O Control provide granular resource controls for VMs.

The vStorage APIs for Data Protection (VADP) provide a backup framework that allows for

the integration of third-party backup solutions into a vSphere implementation.

Master It Which products are licensed features within the VMware vSphere suite?

Master It Which two features of VMware ESXi and VMware vCenter Server together

aim to reduce or eliminate downtime due to unplanned hardware failures?

Master It Name two storage-related features that are new to vSphere 5.5.

Recognize the interaction and dependencies between the products in the vSphere

suite. VMware ESXi forms the foundation of the vSphere product suite, but some features

require the presence of vCenter Server. Features like vMotion, Storage vMotion, vSphere

DRS, vSphere HA, vSphere FT, SIOC, and NIOC require ESXi as well as vCenter Server.

Master It Name three features that are supported only when using vCenter Server

along with ESXi.

Master It Name two features that are supported without vCenter Server but with a li-

censed installation of ESXi.

Understand how vSphere differs from other virtualization products. VMware vSphere’s

hypervisor, ESXi, uses a Type 1 bare-metal hypervisor that handles I/O directly within the

hypervisor. This means that a host operating system, like Windows or Linux, is not required

in order for ESXi to function. Although other virtualization solutions are listed as “Type 1

bare-metal hypervisors,” most other Type 1 hypervisors on the market today require the

presence of a “parent partition” or “dom0” through which all VM I/O must travel.

Master It One of the administrators on your team asked whether he should install

Windows Server on the new servers you purchased for ESXi. What should you tell him,

and why?